From: Jan Kara jack@suse.cz
commit 36369f46e91785688a5f39d7a5590e3f07981316 upstream.
Since commit 10c70d95c0f2 ("block: remove the bd_openers checks in blk_drop_partitions") we allow rereading of partition table although there are users of the block device. This has an undesirable consequence that e.g. if sda and sdb are assembled to a RAID1 device md0 with partitions, BLKRRPART ioctl on sda will rescan partition table and create sda1 device. This partition device under a raid device confuses some programs (such as libstorage-ng used for initial partitioning for distribution installation) leading to failures.
Fix the problem refusing to rescan partitions if there is another user that has the block device exclusively open.
Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20221130135344.2ul4cyfstfs3znxg@quack3 Fixes: 10c70d95c0f2 ("block: remove the bd_openers checks in blk_drop_partitions") Signed-off-by: Jan Kara jack@suse.cz Link: https://lore.kernel.org/r/20221130175653.24299-1-jack@suse.cz [axboe: fold in followup fix] Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- block/blk.h | 2 +- block/genhd.c | 7 +++++-- block/ioctl.c | 12 +++++++----- 3 files changed, 13 insertions(+), 8 deletions(-)
--- a/block/blk.h +++ b/block/blk.h @@ -436,7 +436,7 @@ static inline struct kmem_cache *blk_get } struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu);
-int disk_scan_partitions(struct gendisk *disk, fmode_t mode); +int disk_scan_partitions(struct gendisk *disk, fmode_t mode, void *owner);
int disk_alloc_events(struct gendisk *disk); void disk_add_events(struct gendisk *disk); --- a/block/genhd.c +++ b/block/genhd.c @@ -356,7 +356,7 @@ void disk_uevent(struct gendisk *disk, e } EXPORT_SYMBOL_GPL(disk_uevent);
-int disk_scan_partitions(struct gendisk *disk, fmode_t mode) +int disk_scan_partitions(struct gendisk *disk, fmode_t mode, void *owner) { struct block_device *bdev;
@@ -366,6 +366,9 @@ int disk_scan_partitions(struct gendisk return -EINVAL; if (disk->open_partitions) return -EBUSY; + /* Someone else has bdev exclusively open? */ + if (disk->part0->bd_holder && disk->part0->bd_holder != owner) + return -EBUSY;
set_bit(GD_NEED_PART_SCAN, &disk->state); bdev = blkdev_get_by_dev(disk_devt(disk), mode, NULL); @@ -500,7 +503,7 @@ int __must_check device_add_disk(struct
bdev_add(disk->part0, ddev->devt); if (get_capacity(disk)) - disk_scan_partitions(disk, FMODE_READ); + disk_scan_partitions(disk, FMODE_READ, NULL);
/* * Announce the disk and partitions after all partitions are --- a/block/ioctl.c +++ b/block/ioctl.c @@ -467,9 +467,10 @@ static int blkdev_bszset(struct block_de * user space. Note the separate arg/argp parameters that are needed * to deal with the compat_ptr() conversion. */ -static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode, - unsigned cmd, unsigned long arg, void __user *argp) +static int blkdev_common_ioctl(struct file *file, fmode_t mode, unsigned cmd, + unsigned long arg, void __user *argp) { + struct block_device *bdev = I_BDEV(file->f_mapping->host); unsigned int max_sectors;
switch (cmd) { @@ -527,7 +528,8 @@ static int blkdev_common_ioctl(struct bl return -EACCES; if (bdev_is_partition(bdev)) return -EINVAL; - return disk_scan_partitions(bdev->bd_disk, mode & ~FMODE_EXCL); + return disk_scan_partitions(bdev->bd_disk, mode & ~FMODE_EXCL, + file); case BLKTRACESTART: case BLKTRACESTOP: case BLKTRACETEARDOWN: @@ -605,7 +607,7 @@ long blkdev_ioctl(struct file *file, uns break; }
- ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp); + ret = blkdev_common_ioctl(file, mode, cmd, arg, argp); if (ret != -ENOIOCTLCMD) return ret;
@@ -674,7 +676,7 @@ long compat_blkdev_ioctl(struct file *fi break; }
- ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp); + ret = blkdev_common_ioctl(file, mode, cmd, arg, argp); if (ret == -ENOIOCTLCMD && disk->fops->compat_ioctl) ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);